As measures at puncturing of a pneumatic tire, a spare tire is carried in an automobile or the like. Upon puncturing, the driver replaces the punctured tire with the spare tire.
Incidentally, along with the increase in female drivers, measures have been desired to date that eliminate the need for work to replace a punctured tire with a spare tire. In addition, there has been a desire to minimize or remove a space of placing a spare tire in automobiles and so forth. In response to these demands, a kit for repairing a punctured tire has recently been commercially available that combines rubber latex and a compressor for filling air.
This kit includes a sealing compound (repairing liquid) to be injected into this pneumatic tire when a pneumatic tire put on a four-wheel car, a two-wheeler, or the like is punctured. The sealing compound is a material in which natural rubber or synthetic rubber or latex of a mixture thereof, and an anti-freeze made of water, ethylene glycol or polypropylene glycol, and the like are blended.
In a vehicle only equipped with such a puncture repairing kit, a sealing compound included in a puncture repairing kit is injected into a punctured tire, when the pneumatic tire (hereinafter, simply called a “tire”) put on it is punctured, without replacing the tire and wheel. A hole of a tire caused by a puncture is sealed with this sealing compound for temporary repair of the tire, and then the vehicle is driven to a repair service such as a gas station or the like.
In the repair service, the puncture of the tire temporarily repaired with the sealing compound is repaired and this already repaired tire is put on the vehicle again, or the punctured tire is disposed without repairing, depending on the conditions of the hole of puncture. In either case, the sealing compound needs to be extracted out of the inside of the tire. Concerning the sealing compound extracted out of the inside of the tire, treatment depending on the composition of the sealing compound is carried out so as not to contaminate the environment. Thereafter, the final disposal such as disposal, incineration, or the like must be performed. Such a sealing compound is primarily composed of an aqueous solution having rubber latex dispersed therein, with a resin-based adhesive, a fiber material, an antifreezing agent, a pH adjusting agent, an emulsifying agent and the like added thereto.
Incidentally, a sealing compound injected into a pneumatic tire is recovered in a vessel prior to tire replacement, thereby enabling the prevention of splash of the sealing compound. In this recovery, a hose or the like is connected to the valve fitting hole of the tire and then the sealing compound is recovered in the vessel through this hole or the like and is treated in the form of liquid as an industrial waste liquid. As such, the waste liquid needs to be stored until reaching a specified amount. Moreover, there is a problem in that the work for recovering a sealing compound from the inside of a tire takes time.
For the purpose of the efficient treatment of a sealing compound as described above, the rubber latex in the sealing compound is solidified to be separated from the sealing compound as a solid constituent (solid-liquid separation), and then this solid constituent and the remaining liquid constituent each are preferably separately treated. These specific treating methods involve, for example, for the solid constituent, carrying out the removal of impurities, dewatering, drying and the like, thus enabling reusing (recycling) as a rubber material or incineration, landfill, or the like after dewatering and drying, and for the liquid constituent, carrying out, as required, simple purification treatment such as neutralization, dilution, precipitation and the like, thus enabling discharging to sewer system for industrial waste water.
As a specific measure, a method of treating a sealing compound has been proposed that involves injecting an aqueous organic weak acid solution into a pneumatic tire, aggregating the rubber latex contained in a used sealing compound to adhere to the inner surface of the tire as well as neutralizing the separated fluid and rendering the resulting material unharmful (e.g., see Patent Document 1). This method of treating a sealing compound involves pouring a treating agent having mainly an aqueous acid solution with a pH of 1.6 to 1.8 into a sealing compound comprised of an aqueous basic solution having rubber latex dispersed therein and thereby aggregating the rubber latex in the sealing compound to separate the sealing compound into a solid constituent (rubber latex) and a liquid constituent as well as to neutralize the liquid constituent. Also, Patent Document 1 describes that the acid constituting the treating agent is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid, acetic acid, formic acid, citric acid, tartaric acid, salicylic acid, phthalic acid, malonic acid, maleic acid, chloroacetic acid, dichloroacetic acid, and oxalic acid.
Patent Document 1: Japanese Patent Laid-Open No. 2002-226636